Chocolate Flies at Work

Thank God for chocolate flies. No, we are not talking about chocolate-covered houseflies. That sounds repulsive to us too. We are talking about the tiny flies that are essential to the production of the chocolate we love.

Chocolate comes from the seeds of the cacao tree (Theobroma cacao) which is native to the rainforests of South America. When early tribes in the Amazon and Orinoco River area discovered uses for the cacao tree, they started what became a chocolate craze that is still going on today. From there, interest in the trees and the tasty substance they produce spread to more of northern South America, into Central America, and into Mexico. The Aztecs even used cacao beans as money.

However, growing the cacao beans is not easy. The tiny white flowers that produce the beans require a small insect pollinator. The flowers grow out of the trunk of the tree where pollination by a bird or mammal would not be practical. Even bees or butterflies are too large. That’s where the chocolate flies come in. The pollinators that can do the job are tiny flies, or midges, in the family Ceratopogonidae. They are small enough to get into the flowers, and they are on the right work schedule. The cacao flowers open just before dawn—a time when the midges are most active. It seems like a planned arrangement. They are not really chocolate flies, but they are essential helpers for chocolate farmers.

As farmers began to grow cacao on plantations, the pollination process was not working well. Human pollination of the flowers by hand is a difficult job and not as effective as the work of the little flies. The midges were not doing the job because they prefer the shade of the rainforest over the open spaces of cacao plantations. Coincidentally cacao trees grow well in shady areas.